package oj;

import java.util.Scanner;

/**
 * Created with IntelliJ IDEA
 * Description
 * User：chenshu
 * Date：2023-10-26
 * Time：11:05
 */
public class TestDemo {
    public static String func(String str) {
        StringBuilder ret = new StringBuilder();
        int[] arr = new int[127];
        for(int i = 0; i < str.length(); i++) {
            char ch = str.charAt(i);
            if(arr[ch] == 0) {
                ret.append(ch);
                arr[ch] = 1;
            }
        }
        return ret.toString();
    }
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        while(scan.hasNextLine()) {
            String str = scan.nextLine();
            String ret = func(str);
            System.out.println(ret);
        }
    }
}
